In this post I want to explore some of the research around a topic that particularly interests me. That is, what if you have symptoms of hypothyroidism but levels of TSH are normal? This is something I struggled with myself for many years so I want to share my personal experience and what I have found out through my research.
What is hypothyroidism? Causes and symptoms
Hypothyroidism is the second most common female endocrine (hormone) disorders. There are several causes of an underactive thyroid. The most common cause worldwide is iodine deficiency. However in developed countries, iodine deficiency is rare and the most common cause of hypothyroidism is Hashimoto’s thyroiditis. This is an auto immune condition where a persons own immune system develops antibodies which attack the thyroid gland. Other cases are caused by medical interventions such as thyroid surgery, radiation or certain medications.
Some of the main symptoms of hypothyroidism are:
- Sensitivity to cold
- Tiredness and fatigue
- Dry skin and hair
- Brittle nails
- Low libido
- Weight gain
- Irregular or heavy periods
- Trouble concentrating or poor memory
References are listed at the end of the article, see ref (1)(2)(3)(4)
Testing for hypothyroidism TSH levels
Currently, the main test for diagnosing hypothyroidism or an under-active thyroid is a thyroid function test. This is a blood test to measure levels of two thyroid hormones: thyrotropin aka thyroid-stimulating hormone (TSH) and free thyroxine (FT4). If your blood tests show a high level of TSH and low level of FT4 then you may be diagnosed with hypothyroidism(1). High TSH level with normal FT4 is considered sub-clinical hypothyroidism.
I recently did a full check up using Thriva which included a thyroid function check. This is how the results look along with the ranges for TSH and FT4 hormones. You can also read here for more information on interpreting test results. If you are experiencing symptoms of hypothyroidism and want to check your levels at home, it is a great option. Otherwise you can visit your GP and request a thyroid function test.
Symptoms of hypothyroidism but levels of TSH normal? My experience
But what if your thyroid function test comes back normal? What does it mean if you have symptoms of hypothyroidism but normal levels of TSH? Well, you wouldn’t be alone in that regard! It is something that I experienced and I am sure many other women too.
For several years I experienced symptoms of hypothyroidism. In particular disruption to my menstrual cycles, feeling cold and tired all of the time, frequent constipation and dry and thinning hair. I was a classic case of hypothyroidism, exhibiting nearly all of the listed symptoms. However, I had several thyroid function tests during this time which all came back perfectly normal. I couldn’t understand what was going on and was left feeling frustrated and confused.
Each time I left the doctors office I would feel so down and hopeless. It wasn’t that I wanted something to be wrong with me. I just wanted answers so I could get my health back on track! There is nothing worse than feeling like your body is malfunctioning and not knowing what you can do to fix it.
Me whilst dealing with hypothyroid symptoms (L) and well into the healing process (R)
Symptoms of hypothyroidism but levels of TSH normal? The science
During this time I did a lot of research into all things hormone related. I found some interesting articles about patients with symptoms of hypothyroidism but normal levels of TSH. In some cases this related to sub-clinical hypothyroidism where levels of TSH were slightly elevated and FT4 levels were normal. This didn’t really interest me as in my case, both my TSH and FT4 levels were normal. But if your levels of TSH are between 2.5 and 4mIU/L, as you have the symptoms above, it is definitely possible that you are experiencing sub-clinical hypothyroidism.
Another study that interested me concluded that measuring blood levels of TSH may not be a reliable diagnostic test for hypothyroid (5). They describe case studies of two patients with symptoms of hypothyroidism but normal levels of TSH. When tested using alternative methods, both patients were confirmed as hypothyroid, despite normal TSH levels. Even more interesting, their symptoms went away when treated for hypothyroidism! The theory is that despite normal levels of thyroid hormones in the blood, if the cells are resistant to their effects, we can still experience symptoms of hypothyroidism.
Another area of research that caught my eye is something I have been reading and writing a lot about lately: low metabolism. In particular, I have shared posts about the signs and causes of a low metabolism and how to speed up a low metabolism. This turned out to be the answer to my problems. But how does this link to hypothyroidism? As I mentioned in those previous posts, the symptoms of hypothyroidism overlap greatly with those of a low metabolism. So perhaps if your doctor has given you the all clear with regards to your thyroid health, you might want to consider taking action to support your metabolism.
Reduce hypothyroidism symptoms by supporting your metabolism
To reduce hypothyroidism symptoms by supporting your metabolism, you want to focus on the following four areas:
- Eating a metabolism supporting diet
- Correct breathing and movement
- Prioritising stress reduction
- Getting good quality sleep
Now, as a Nutritionist and Women’s Wellness Coach, this is an area that interests me greatly. A low metabolic rate can affect all aspects of your wellbeing from your energy levels to your mood and mindset. If your metabolism is slow, you can also find it difficult to lose weight despite eating healthily and exercising. So focusing on improving metabolic rate can have a wide range of benefits as well as helping to reduce hypothyroidism symptoms.
I will be continuing to share more details on how to do this over the next weeks and months. So make sure to follow my blog by adding your email to the “Subscribe by email” panel on the right to be updated by email when I post.
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